KR20120042367A - Optical unit and organic light emitting diode display having the same - Google Patents

Abstract

PURPOSE: An optical unit and an organic light emitting diode display having the same are provided to minimize the loss of light irradiated from an organic light emitting device. CONSTITUTION: An organic light emitting diode display(100) comprises an optical unit(58). The optical unit comprises a polarizing plate(585), a second polarizing plate(581), and a phase delay plate(586). The first polarizing plate is located on a light emitting unit. The second polarizing plate is located on the first polarizing plate and has polarization degree higher than the first polarizing plate. A plurality of phase delay plates locates between the first polarizing plate and second polarizing plate.

Description

Optical unit and organic light emitting display device including the same {OPTICAL UNIT AND ORGANIC LIGHT EMITTING DIODE DISPLAY HAVING THE SAME}

The present invention relates to an optical unit, and more particularly, to an optical unit for improving light characteristics and an organic light emitting display device including the same.

BACKGROUND ART [0002] A display device is an apparatus for displaying an image. Recently, an organic light emitting diode (OLED) display has attracted attention.

The OLED display has a self-emission characteristic, and unlike a liquid crystal display device, a separate light source is not required, so that the thickness and weight can be reduced. Further, the organic light emitting display device exhibits high-quality characteristics such as low power consumption, high luminance, and high reaction speed.

The conventional organic light emitting diode display includes an organic light emitting diode (OLED) for displaying an image emitting light, wherein external light is reflected by an electrode or the like constituting the organic light emitting diode to display the organic light emitting diode. There was a problem that the display quality of the image is degraded.

Recently, in order to suppress such external light reflection, there has been a configuration in which a polarizing plate and a phase retardation plate are disposed on an organic light emitting element to suppress external light reflection. When the light is emitted to the outside through the polarizing plate and the phase retardation plate, there is a problem that a large portion is lost together.

One embodiment of the present invention is to solve the above-described problems, and to provide an optical unit and an organic light emitting display including the same to suppress the external light reflection and minimize the loss of light emitted from the organic light emitting device.

A first aspect of the present invention for achieving the above technical problem is an optical unit disposed on a light emitting unit for emitting light, the first polarizing plate positioned on the light emitting unit, the first polarizing plate located on the first polarizing plate And an optical unit including a second polarizing plate having a higher degree of polarization than the first polarizing plate, and a plurality of phase retardation plates positioned between the first polarizing plate and the second polarizing plate.

The first polarizer may have a higher transmittance than the second polarizer.

The first polarizer may include a matrix, iodine and a dye.

The weight ratio of the iodine and the dye may be 1: 1 to 1: 2.

The pier between the polarization axis of the first polarizing plate and the polarization axis of the second polarizing plate may be 45 degrees.

The plurality of phase retardation plates may include a first phase retardation plate, which is a half wave plate positioned between the first polarizing plate and the second polarizing plate, and a quarter positioned between the first polarizing plate and the first phase retardation plate. A second phase retardation plate, which is a wavelength plate, and a third phase retardation plate, which is a quarter wave plate positioned between the first polarizing plate and the second phase retardation plate, may be included.

The pier between the polarization axis of the second polarizing plate and the optical axis of the first phase retardation plate may be 17.5 degrees to 27.5 degrees, and the pier between the polarization axis of the first polarizing plate and the optical axis of the first phase retardation plate may be 17.5 degrees to 27.5 degrees. .

The pier between the polarization axis of the second polarizing plate and the optical axis of the second phase retardation plate may be 40 degrees to 50 degrees, and the pier between the polarization axis of the first polarizing plate and the optical axis of the second phase retardation plate may be 0 degrees to 5 degrees. .

The pier between the polarization axis of the second polarizing plate and the optical axis of the third phase retardation plate may be 85 degrees to 90 degrees, and the pier between the polarization axis of the first polarizing plate and the optical axis of the third phase retardation plate may be 40 degrees to 50 degrees. .

The pier between the optical axis of the second phase retardation plate and the optical axis of the third phase retardation plate may be 45 degrees.

The plurality of phase retardation plates are an additional phase retardation plate which is a half wave plate disposed between the first polarizing plate and the second polarizing plate and a quarter wavelength disposed between the first polarizing plate and the first phase retardation plate. And a fifth phase retardation plate that is a plate.

The pier between the polarization axis of the second polarizing plate and the optical axis of the fourth phase retardation plate may be 10 degrees to 20 degrees, and the pier between the polarization axis of the first polarizing plate and the optical axis of the fourth phase retardation plate may be 25 degrees to 35 degrees. .

The pier between the polarization axis of the second polarizing plate and the optical axis of the fifth phase retardation plate may be 70 degrees to 80 degrees, and the pier between the polarization axis of the first polarizing plate and the optical axis of the fifth phase retardation plate may be 25 degrees to 35 degrees. .

The apparatus may further include an additional phase retardation plate disposed between the light emitting unit and the first polarizing plate.

The pier between the optical axis of the additional phase retardation plate and the polarization axis of the first polarizer may be between 40 degrees and 50 degrees.

In addition, a second aspect of the present invention includes a first electrode, a second electrode positioned on the first electrode, and an organic light emitting layer positioned between the first electrode and the second electrode, and emits light. An organic light emitting display device is disposed on an element and the organic light emitting element and includes the optical unit.

According to some embodiments of the above-described problem solving means of the present invention, there is provided an optical unit and an organic light emitting display device including the same, which suppresses reflection of external light and minimizes the loss of light emitted from the organic light emitting element.

1 is a cross-sectional view of an organic light emitting diode display according to a first exemplary embodiment of the present invention.
2 is a layout view illustrating a circuit arrangement of a driving circuit unit and an organic light emitting diode of an organic light emitting diode display according to a first exemplary embodiment of the present invention.
3 and 4 are cross-sectional views and configuration diagrams illustrating paths of light introduced from the outside into the organic light emitting diode display according to the first exemplary embodiment.
5 is a diagram illustrating a degree of loss of light introduced into the organic light emitting diode display according to the first exemplary embodiment of the present invention.
6 and 7 are cross-sectional views and configuration diagrams illustrating a path through which light emitted from an organic light emitting diode of the organic light emitting diode display according to the first exemplary embodiment is emitted to the outside.
FIG. 8 is a diagram illustrating a loss degree of light radiated from the organic light emitting diode of the organic light emitting diode display according to the first exemplary embodiment of the present invention.
9 is a cross-sectional view of an organic light emitting diode display according to a second exemplary embodiment of the present invention.
10 and 11 are cross-sectional views and configuration diagrams illustrating a path of light introduced from the outside into the organic light emitting diode display according to the second exemplary embodiment.
12 and 13 are cross-sectional views and configuration diagrams showing a path through which light generated from an organic light emitting diode of the organic light emitting diode display according to the second exemplary embodiment of the present invention is emitted to the outside.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification.

In addition, in the various embodiments, components having the same configuration are represented by the same reference symbols in the first embodiment. In the other embodiments, only components different from those in the first embodiment will be described .

In addition, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of description, the present invention is not necessarily limited to the illustrated.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. It will be understood that when a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the other portion "directly on" but also the other portion in between.

In addition, throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding the other components unless otherwise stated. Also, throughout the specification, the term "on " means to be located above or below a target portion, and does not necessarily mean that the target portion is located on the image side with respect to the gravitational direction.

Hereinafter, an organic light emitting diode display according to a first exemplary embodiment will be described with reference to FIGS. 1 to 8.

1 is a cross-sectional view of an organic light emitting diode display according to a first exemplary embodiment of the present invention.

As shown in FIG. 1, the organic light emitting diode display 100 according to the first exemplary embodiment includes a first substrate 51, a second substrate 52, and an optical unit 58 bonded to each other. do.

The first substrate 51 includes a substrate member 511, a driving circuit portion DC formed on the substrate member 511, and an organic light emitting element L1 formed on the driving circuit portion DC and serving as a light emitting unit. do.

2 is a layout view illustrating a circuit arrangement of a driving circuit unit and an organic light emitting diode of an organic light emitting diode display according to a first exemplary embodiment of the present invention.

As shown in FIG. 2, the driving circuit unit DC generally has an arrangement structure as illustrated in FIG. 2. That is, as shown in FIG. 2, the driving circuit unit DC includes two or more thin film transistors T1 and T2 and one or more capacitors C1. The thin film transistor basically includes a switching transistor T1 and a driving transistor T2.

Meanwhile, although the first embodiment of the present invention has a 2Tr-1Cap structure, the organic light emitting diode display according to another embodiment of the present invention may include three or more thin film transistors and two or more capacitors, and additional wiring is further formed. It may be formed to have a variety of structures. As such, the thin film transistor and capacitor further formed may be a configuration of a compensation circuit.

The switching transistor T1 is connected to the scan line SL1 and the data line DL1, and converts the data voltage input from the data line DL1 into the driving transistor T2 according to the switching voltage input to the scan line SL1. send. The capacitor C1 is connected to the switching transistor T1 and the power line VDD, and stores a voltage corresponding to a difference between the voltage received from the switching transistor T1 and the voltage supplied to the power line VDD.

The driving transistor T2 is connected to the power line VDD and the capacitor C1 to convert the output current I _OELD proportional to the square of the difference between the voltage stored in the capacitor C1 and the threshold voltage to the organic light emitting element L1. The organic light emitting element L1 emits light by the output current I _OLED .

Referring again to FIG. 1, the driving transistor T2 includes a source electrode 533, a drain electrode 532, and a gate electrode 531.

The organic light emitting element L1 emits light to display an image, and is formed on the first electrode 544, the organic emission layer 545 formed on the first electrode 544, and the organic emission layer 545. The second electrode 546 is included. That is, the second electrode 546 is positioned on the first electrode 544, and the organic emission layer 545 is positioned between the first electrode 544 and the second electrode 546. In general, the first electrode 544 becomes an anode electrode, and the second electrode 546 becomes a cathode electrode. However, the first embodiment according to the present invention is not limited thereto, and the first electrode 544 may be a cathode and the second electrode 546 may be an anode according to a driving method. The first electrode 544 of the organic light emitting element L1 is connected to the drain electrode 532 of the driving transistor T2. At least one of the first electrode 544 and the second electrode 546 is formed in a transflective or reflective type to reflect light.

In the organic light emitting diode display 100 according to the first exemplary embodiment, the organic light emitting diode L1 emits light toward the second electrode 546 in the organic light emitting layer 545 to display an image. That is, the organic light emitting diode display 100 is made of a top emission type.

The optical unit 58 suppresses reflection of external light by the organic light emitting element L1, which is a light emitting unit, thereby improving visibility of the organic light emitting diode display 100, and loss of light emitted from the organic light emitting element L1 to the outside is reduced. Minimize the role. The optical unit 58 includes a first polarizer 585, a second polarizer 581, and a plurality of phase delay plates 582, 583, and 584.

The first polarizer 585 is disposed on the organic light emitting element L1, which is a light emitting unit from which light is emitted, and the second polarizer 581 is disposed on the first polarizer 585. A plurality of phase delay plates 582, 583, and 584 are disposed between the first polarizer 585 and the second polarizer 581. The plurality of phase retardation plates may include a first phase retardation plate 582 disposed between the first polarization plate 585 and the second polarization plate 581, and a space between the first polarization plate 585 and the first phase retardation plate 582. The second phase retardation plate 583 is disposed, and the third phase retardation plate 584 is disposed between the first polarizing plate 585 and the second phase retardation plate 583. That is, a third phase delay plate 584, a second phase delay plate 583, and a first phase delay plate 582 are sequentially stacked on the first polarizing plate 585.

In addition, the optical unit 58 further includes an additional phase retardation plate 586 disposed between the first polarizing plate 585 and the organic light emitting element L1. Hereinafter, the additional phase delay plate is referred to as an additional phase delay plate 586. However, the first embodiment according to the present invention is not limited thereto. Therefore, the additional phase delay plate 586 may be omitted in some cases.

The first polarizing plate 585 and the second polarizing plate 581 each have a polarization axis, and linearly polarize light in the polarization axis direction. Specifically, the first polarizing plate 585 and the second polarizing plate 581 pass light corresponding to each polarization axis, and absorb light that does not coincide with the polarization axis. Accordingly, when light passes through the first polarizing plate 585 and the second polarizing plate 581, the light is linearly polarized in the respective polarization axis directions.

The second polarizer 581 has a higher polarization than the first polarizer 585, but has a low transmittance. That is, the first polarizer 585 has a higher transmittance than the second polarizer 581, but a low polarization degree. Accordingly, when light is transmitted through the first polarizing plate 585, light loss is lower than that of the second polarizing plate 581, but the polarization degree is lowered.

The first polarizer 585 has a matrix structure, and specifically, includes a matrix, iodine and a dye. Here, the matrix may be made of polyvinyl alcohol (PVA).

The first polarizer 585 includes iodine, dye, and polyvinyl alcohol at the same time. The concentration of one or more of iodine, dye, and polyvinyl alcohol may be lowered to improve the transmittance of the first polarizer 585 and at the same time lower the degree of polarization.

On the other hand, when only the iodine is included in the polyvinyl alcohol to form a polarizing plate, the polarizing plate is polarized while the iodine ion chain is oriented by the oriented polyvinyl alcohol chain. As such, when the polyvinyl alcohol contains only iodine, polarization efficiency and transmittance of the polarizing plate may be excellent, but due to the sublimability of iodine, temperature and humidity and durability to light may be degraded, and thus uniformity of the polarizing plate may be reduced. Thus, when only the dye is included in the polyvinyl alcohol to form a polarizing plate, similarly to the case of using only iodine, the dye is oriented by the polyvinyl alcohol chains oriented in the stretched direction, and the polarization is shown on the polarizing plate. However, when the polyvinyl alcohol includes only the dye, the dye may not have sublimation such as iodine, and thus the durability of the polarizing plate may be excellent, but the dichroism of the polarizing plate may be poor.

Therefore, the uniformity of the first polarizing plate 585 in which the iodine having excellent uniformity and the dye having excellent durability are simultaneously included in the polyvinyl alcohol is complemented by the dye to compensate for the lack of uniformity of iodine.

The first polarizing plate 585 has an absorption axis and a polarization axis, and the absorption axis is an axis in which iodine ion chains and dye ion chains are stretched and oriented, and one of two vertical components of light vibrating in an arbitrary direction is the first polarizing plate ( It interacts with the electrons of 585 to dissipate its components in the process of converting the electrical energy of light into the energy of the electrons, and the polarization axis is an axis perpendicular to the absorption axis and transmits light oscillating in the polarization axis direction.

The first polarizing plate 585 is a method of bonding the iodine and dye after stretching the polyvinyl alcohol film, the method of adsorbing and stretching the iodine and dye on the polyvinyl alcohol film, and dyeing the iodine and dye on the polyvinyl alcohol film It can manufacture by the method of extending | stretching simultaneously.

The weight ratio of iodine and dye used in the first polarizing plate 585 may be 1: 1 to 1: 2. When the weight ratio of iodine and dye satisfies the above range, both the uniformity and the polarization degree of the first polarizing plate 585 are excellent without being lowered. The thickness of the first polarizing plate 585 may be 15 to 30 μm as a typical range.

Such an pier between the polarization axis of the first polarizing plate 585 and the polarization axis of the second polarizing plate 581 is 45 degrees.

The first phase retardation plate 582 is a half wave plate, and the first phase retardation plate 582 has an optical axis that is twisted by an angle within a range of 17.5 degrees to 27.5 degrees from the polarization axis of the second polarizing plate 581. That is, the pier between the optical axis of the first phase retardation plate 582 and the polarization axis of the second polarizing plate 581 is in the range of 17.5 degrees to 27.5 degrees. Further, the pier between the optical axis of the first phase retardation plate 582 and the polarization axis of the first polarizing plate 585 also falls within the range of 17.5 degrees to 27.5 degrees.

The second phase retardation plate 583 is a quarter wave plate, and the second phase retardation plate 583 has an optical axis that is twisted by an angle within a range of 40 degrees to 50 degrees from the polarization axis of the second polarizing plate 581. That is, the pier between the optical axis of the second phase retardation plate 583 and the polarization axis of the second polarizing plate 581 is in the range of 40 degrees to 50 degrees. Further, the pier between the optical axis of the second phase retardation plate 583 and the polarization axis of the first polarizing plate 585 is within the range of 0 degrees to 5 degrees.

The third phase retardation plate 584 is a quarter wave plate, and the third phase retardation plate 584 has an optical axis that is shifted by an angle within a range of 85 to 95 degrees from the polarization axis of the second polarizing plate 581. That is, the pier between the optical axis of the third phase retardation plate 584 and the polarization axis of the second polarizing plate 581 is in the range of 85 to 95 degrees. Further, the pier between the optical axis of the third phase retardation plate 584 and the polarization axis of the first polarizing plate 585 is within a range of 40 degrees to 50 degrees.

The additional phase retardation plate 586 is a quarter wave plate, and the additional phase retardation plate 586 has an optical axis that is twisted by an angle within a range of 40 degrees to 50 degrees from the polarization axis of the first polarizing plate 585.

The second substrate 52 covers the first substrate 51 on which the organic light emitting element L1 and the driving circuit unit DC are formed. That is, the second substrate 52 is disposed to face the first substrate 51 to cover the thin film transistors T1 and T2, the power storage element C1, the organic light emitting element L1, and the like to be sealed from the outside. At this time, although not shown, the second substrate 52 is bonded to each other with the first substrate 51 through a sealant formed along an edge to seal the space between the two substrates 51 and 52.

In addition, although the optical unit 58 formed on the organic light emitting element L1 is attached on the second substrate 52, the present invention is not necessarily limited thereto. Therefore, the optical unit 58 may be positioned between the second substrate 52 and the organic light emitting element L1 and covered by the second substrate 52. That is, the optical unit 58 may be disposed in a sealing space in which the first substrate 51 and the second substrate 52 are bonded to each other. As such, the position of the optical unit 58 may be freely disposed as long as the light is emitted from the light emitting unit on the organic light emitting element L1.

By such a configuration, the organic light emitting diode display 100 may effectively suppress reflection of external light to improve visibility and minimize loss of light emitted from the organic light emitting layer 545 to the outside. That is, display characteristics of the organic light emitting diode display 100 may be improved.

In addition, the organic light emitting diode display 100 may efficiently emit light generated by the organic light emitting layer 545 to the outside, thereby reducing power consumption and improving lifespan.

3 to 9, the light emitted from the organic light emitting layer 545 to the outside while the optical unit 58 of the organic light emitting diode display 100 according to the first exemplary embodiment of the present invention effectively suppresses reflection of external light. Let's look at the principle of minimizing losses.

First, the light passing through the optical unit 58 around the visible light will be described as follows. Visible light is classified by color. That is, blue light of visible light has a wavelength within a range of about 420 nm to 480 nm. Green light has a wavelength around 550 nm and red light has a wavelength around 650 nm.

As such, since the visible light has different wavelengths for each color, the change that the visible light passes through the optical unit 58 is generally similar, but slightly different for each color. Accordingly, the optical unit 58 may include each of the plurality of phase delay plates 582, 583, and 584 in consideration of the main color included in the external light to suppress reflection or the state of light emitted from the organic light emitting element L1. The optical axis of is set to have an appropriate angle within the above-described range.

Hereinafter, the operation principle of the optical unit 58 will be described in detail by taking the optical unit 58 arranged as an example to minimize the loss of blue light among the light emitted from the organic light emitting element L1 and to emit it to the outside. do. This arrangement of the optical unit 58 may be appropriate when the luminance of blue light among the light emitted from the organic light emitting element L1 is relatively low.

However, when visible light other than blue light passes through the optical unit 58 according to an example, it does not behave differently from blue light. That is, visible light other than blue light behaves substantially the same as blue light while passing through the optical unit 58. However, visible light other than blue light has a slightly different behavior as it has a wavelength different from that of blue light, and thus, visible light other than blue light has a slightly lower transmittance when passing through the optical unit 58 according to an example than blue light. Can be seen. In view of the above, the present specification will use the expression that is substantially the same for the behavior of all visible light, including blue light.

First, referring to FIGS. 3 to 5, the path of light flowing into the inside through the optical unit 58 from the outside will be described.

3 and 4 are cross-sectional views and configuration diagrams illustrating paths of light introduced from the outside into the organic light emitting diode display according to the first exemplary embodiment. 5 is a diagram illustrating a degree of loss of light introduced into the organic light emitting diode display according to the first exemplary embodiment of the present invention.

3 to 5, external light having various phases mixed therein is linearly polarized in the polarization axis direction of the second polarizing plate 581 while passing through the second polarizing plate 581. The light which has become linearly flat light passes through the first phase retardation plate 582, which is a half wave plate, and rotates 45 degrees while maintaining the linearly polarized state. At this time, the optical axis of the first phase retardation plate 582 is twisted by 22.5 degrees than the polarization axis of the second polarizing plate 581. That is, the pier between the optical axis of the first phase retardation plate 582 and the polarization axis of the second polarizing plate 581 is 22.5 degrees.

Next, the linearly flattened light rotated 45 degrees passes through the second phase retardation plate 583, which is a quarter wave plate, as it is, without substantial change. At this time, the optical axis of the second phase retardation plate 583 is shifted by 45 degrees from the polarization axis of the second polarizing plate 581. That is, the angle of intersection between the optical axis of the second phase retardation plate 583 and the polarization axis of the second polarizing plate 581 is 45 degrees.

As described above, since the axial direction of the linearly-lighted light rotated 45 degrees through the first phase retardation plate 582 and the optical axis direction of the second phase retardation plate 583 are substantially the same, the light remains as it is without substantial change. It passes through the two phase retardation plate 583. As described above, substantially the same means that visible light is distributed in various wavelengths for each color, and thus, axial directions of all the light passing through the first phase retardation plate 582 are not completely identical to each other.

Next, the linearly polarized light rotated 45 degrees through the second phase retardation plate 583 as it passes through the third phase retardation plate 584, which is a quarter wave plate, is changed into circularly polarized light. At this time, the optical axis of the third phase retardation plate 584 is twisted by 90 degrees than the polarization axis of the second polarizing plate 581. That is, the angle of intersection between the optical axis of the third phase retardation plate 584 and the polarization axis of the second polarizing plate 581 is 90 degrees.

As described above, since the pier between the axial direction of the linearly flattened light rotated by 45 degrees and the optical axis direction of the third phase retardation plate 584 forms 45 degrees, the linearly polarized light passes through the third phase retardation plate 584. It turns into circularly polarized light.

Next, light that is circularly polarized by passing through the third phase retardation plate 584 is linearly polarized in the direction of the polarization axis of the first polarizing plate 585 while passing through the first polarizing plate 585, and light that is not linearly polarized is absorbed. That is, only a portion of the circularly polarized light having a component coinciding with the polarization axis of the first polarizer 585 passes through the first polarizer 585, and since most of the remaining light does not coincide with the polarization axis, the first polarizer 585. Absorbed and extinguished. In this case, since the first polarizing plate 585 has a higher transmittance and a lower polarization degree than the second polarizing plate 581, the amount of light that is external light is smaller than that of the first polarizing plate 585 when passing through the second polarizing plate 581. Absorbed and extinguished. That is, when light passes through the first polarizing plate 585, the degree of loss of light becomes small.

As such, since a portion of the circularly polarized light disappears while passing through the first polarizer 585, the organic light emitting diode display 100 may have an effect of suppressing reflection of external light.

Next, the linearly polarized light passing through the first polarizer 585 is circularly polarized again while passing through the additional phase retardation plate 586, and is then reflected by the electrodes 544 and 546 of the organic light emitting element L1 to be axially oriented. This 180 degrees will change. In addition, the light may be reflected not only on the electrodes 544 and 546 of the organic light emitting element L1 but also on various metal wires.

Next, the circularly polarized light of which the axial direction is changed by 180 degrees is linearly polarized again while passing through the additional phase retardation plate 586, and then absorbed and extinguished by the first polarizing plate 585.

As such, the remaining light passing through the first polarizer 585 passes through the additional phase delay plate 586, is reflected by the organic light emitting element L1, and then passes through the additional phase delay plate 586. Since it is extinguished by the first polarizer 585, the organic light emitting diode display 100 may have an effect of suppressing reflection of external light.

By such a configuration, the light flowing into the inside through the optical unit 58 from the outside is mostly extinguished in the first polarizing plate 585. Therefore, the organic light emitting diode display 100 may effectively suppress reflection of external light to improve visibility.

Next, the path of light emitted from the organic light emitting layer 545 (shown in FIG. 1) to the outside will be described with reference to FIGS. 6 to 8.

6 and 7 are cross-sectional views and configuration diagrams illustrating a path through which light emitted from an organic light emitting diode of the organic light emitting diode display according to the first exemplary embodiment is emitted to the outside. FIG. 8 is a diagram illustrating a loss degree of light radiated from the organic light emitting diode of the organic light emitting diode display according to the first exemplary embodiment of the present invention.

Light emitted from the organic emission layer 545 passes through the second electrode 546 and the additional phase delay plate 586 in turn. At this time, the light is a state in which various phases are mixed.

Next, light passing through the additional phase retardation plate 586 is directed to the first polarizer 585. At this time, light that matches the polarization axis of the first polarizing plate 585 among the light passing through the additional phase retardation plate 586 is linearly flattened while passing through the first polarizing plate 585. At this time, since the first polarizing plate 585 has a higher transmittance and a lower polarization degree than the second polarizing plate 581, the amount of light that is internal light is smaller than that of the first polarizing plate 585 when passing through the second polarizing plate 581. Absorbed and extinguished. That is, when light passes through the first polarizing plate 585, the degree of loss of light becomes small.

The linearly polarized light passing through the first polarizing plate 585 becomes circularly polarized light while passing through the third phase retardation plate 584 which is a quarter wave plate. At this time, the optical axis of the third phase retardation plate 584 is shifted by 45 degrees from the polarization axis of the first polarizing plate 585. That is, the angle of intersection between the optical axis of the third phase retardation plate 584 and the polarization axis of the first polarizing plate 585 is 45 degrees.

As such, the pier between the axial direction of the linearly polarized light passing through the first polarizing plate 585 and the optical axis direction of the third phase retardation plate 584 is 45 degrees, so that the linearly polarized light is the third phase retardation plate 584. ), It becomes circularly polarized light.

Next, the circularly polarized light passing through the third phase retardation plate 584 becomes linearly polarized light while passing through the second phase retardation plate 583 which is a quarter wave plate. At this time, the optical axis of the second phase retardation plate 583 is the same as the polarization axis of the first polarizing plate 585. Accordingly, light circularly polarized through the third phase retardation plate 584 is linearly polarized in the same manner as it was linearly polarized before passing through the third phase retardation plate 584 while passing through the second phase retardation plate 583. That is, the linearly polarized light passing through the first polarizing plate 585 and the linearly polarized light passing through the second phase retardation plate 583 are substantially the same.

Next, the linearly polarized light passing through the second phase retardation plate 583 rotates 45 degrees while maintaining the linear polarization while passing through the first phase retardation plate 582 which is a half wave plate. At this time, the optical axis of the first phase retardation plate 582 is twisted by 22.5 degrees than the polarization axis of the first polarizing plate 585. That is, the pier between the optical axis of the first phase retardation plate 582 and the polarization axis of the first polarizing plate 585 is 22.5 degrees.

In addition, the axial direction of the linearly polarized light rotated 45 degrees through the first phase retardation plate 582 is substantially the same as the polarization axis direction of the second polarizing plate 581. Accordingly, the linearly flattened light rotated 45 degrees passes through the second polarizer 581 as it is, without substantial loss, and is emitted to the outside.

By such a configuration, light emitted from the organic light emitting element L1 is mostly emitted through the optical unit 58 without being greatly lost. In the conventional structure in which one polarizing plate and one phase retardation plate are arranged, only about 40% of the light generated by the organic light emitting element L1 is emitted to the outside. In contrast, in the organic light emitting diode display 100 according to the first exemplary embodiment, about 60% to 80% of the light generated by the organic light emitting element L1 passes through the optical unit 58 and is effectively emitted to the outside. It could be confirmed through experiments. Therefore, the loss of light emitted from the organic light emitting layer 545 to the outside by the optical unit 58 is minimized.

In addition, the organic light emitting diode display 100 may efficiently emit light generated by the organic light emitting layer 545 to the outside, thereby reducing power for driving the organic light emitting layer 545, and thus, the organic light emitting diode display ( 100) lifespan is improved.

Meanwhile, although the optical unit 58 included in the organic light emitting diode display 100 according to the first exemplary embodiment of the present invention is disposed on the organic light emitting element L1, in another exemplary embodiment of the present invention, the optical unit 58 is used. ) May be disposed on a light emitting unit such as a liquid crystal display device (LCD) or a plasma display panel (PDP) or on a light emitting unit such as an illumination.

Hereinafter, the organic light emitting diode display 200 according to the second exemplary embodiment will be described with reference to FIG. 9.

9 is a cross-sectional view of an organic light emitting diode display according to a second exemplary embodiment of the present invention.

As shown in FIG. 9, the organic light emitting diode display 200 according to the second exemplary embodiment of the present invention includes a first substrate 51, a second substrate 52, and an optical unit 59 bonded to each other. do.

The optical unit 59 includes a first polarizer 595, a second polarizer 591, and a plurality of phase delay plates 592 and 593.

The first polarizer 595 is disposed on the organic light emitting element L1, and the second polarizer 591 is disposed on the first polarizer 595. A plurality of phase delay plates 592 and 593 are disposed between the first polarizer 595 and the second polarizer 591. The plurality of phase retardation plates may include a fourth phase retardation plate 592 disposed between the first polarization plate 595 and the second polarization plate 591, and between the first polarization plate 595 and the fourth phase retardation plate 592. A fifth phase delay plate 593 disposed. That is, the fifth phase delay plate 593 and the fourth phase delay plate 592 are sequentially stacked on the first polarizing plate 595.

In addition, the optical unit 59 further includes an additional phase retardation plate 597 disposed between the first polarizing plate 595 and the organic light emitting element L1. Hereinafter, the additional phase delay plate is referred to as a sixth phase delay plate 597. However, the second embodiment according to the present invention is not limited thereto. Therefore, the sixth phase delay plate 597 may be omitted in some cases.

The pier between the polarization axis of the first polarizing plate 595 and the polarization axis of the second polarizing plate 591 is 45 degrees.

The fourth phase retardation plate 592 is a half wave plate, and the fourth phase retardation plate 592 has an optical axis that is shifted by an angle within a range of 10 to 20 degrees from the polarization axis of the second polarizing plate 591. That is, the pier between the optical axis of the fourth phase retardation plate 592 and the polarization axis of the second polarizing plate 591 is in the range of 10 degrees to 20 degrees. Further, the pier between the optical axis of the fourth phase retardation plate 592 and the polarization axis of the first polarizing plate 595 falls within a range of 25 degrees to 35 degrees.

The fifth phase retardation plate 593 is a quarter wave plate, and the fifth phase retardation plate 593 has an optical axis that is twisted by an angle within a range of 70 to 80 degrees from the polarization axis of the second polarizing plate 591. That is, the pier between the optical axis of the fifth phase retardation plate 593 and the polarization axis of the second polarizing plate 591 is in the range of 70 to 80 degrees. Further, the pier between the optical axis of the fifth phase retardation plate 593 and the polarization axis of the first polarizing plate 595 falls within a range of 25 degrees to 35 degrees.

The sixth phase retardation plate 597 is a quarter wave plate, and the sixth phase retardation plate 597 is an optical axis that is twisted by an angle within a range of 40 degrees to 50 degrees from the polarization axis of the reflective first polarizing plates 595 and 596. Has

By such a configuration, the organic light emitting diode display 200 effectively suppresses reflection of external light, thereby improving visibility of an image displayed by the organic light emitting element L1, and at the same time, loss of light emitted from the organic light emitting layer 545 to the outside. This is minimized. That is, display characteristics of the organic light emitting diode display 200 are improved.

In addition, the organic light emitting diode display 200 may efficiently emit light generated by the organic light emitting layer 545 to the outside, thereby reducing power consumption and improving lifespan.

Hereinafter, the light emitted from the organic light emitting layer 545 to the outside while the optical unit 59 of the organic light emitting diode display 100 according to the second exemplary embodiment of the present invention effectively suppresses reflection of external light will be described with reference to FIGS. 10 to 13. Let's look at how to minimize the loss of

Hereinafter, as in the first embodiment, the optical unit 59 is an example of the optical unit 59 arranged to emit the light while minimizing the loss of the blue light among the light emitted from the organic light emitting element L1. The principle of operation is explained in detail.

However, visible light other than blue light does not behave differently from blue light when passing through the optical unit 59 according to an example. That is, visible light other than blue light behaves substantially the same as blue light while passing through the optical unit 59. However, as the visible light other than the blue light has a wavelength different from that of the blue light, a slight difference occurs in the behavior. Thus, visible light other than blue light may show a slightly lower transmittance when passing through the optical unit 59 according to an example than blue light, as described above in the first embodiment.

First, referring to FIGS. 10 and 11, the path of light flowing into the inside through the optical unit 59 from the outside will be described.

10 and 11 are cross-sectional views and configuration diagrams illustrating a path of light introduced from the outside into the organic light emitting diode display according to the second exemplary embodiment.

10 and 11, external light having various phases mixed therein is linearly polarized in the polarization axis direction of the second polarizing plate 591 while passing through the second polarizing plate 591. The linearly flattened light rotates 30 degrees while maintaining the linearly polarized light while passing through the fourth phase retardation plate 592 which is a half wave plate again. At this time, the optical axis of the fourth phase retardation plate 592 is distorted by 15 degrees from the polarization axis of the second polarizing plate 591. That is, the angle of intersection between the optical axis of the fourth phase retardation plate 592 and the polarization axis of the second polarizing plate 591 is 15 degrees.

Next, the linearly flattened light rotated 30 degrees changes to circularly polarized light while passing through the fifth phase retardation plate 593 which is a quarter wave plate. At this time, the optical axis of the fifth phase retardation plate 593 is distorted by 75 degrees from the polarization axis of the second polarizing plate 591. That is, the angle of intersection between the optical axis of the fifth phase retardation plate 593 and the polarization axis of the second polarizing plate 591 is 75 degrees.

As described above, since the pier between the axial direction of the linearly-flattened light rotated 30 degrees and the optical axis direction of the fifth phase retardation plate 593 forms 45 degrees, the light passes through the fifth phase retardation plate 593. It becomes polarized light.

Next, the circularly polarized light passing through the fifth phase retardation plate 593 is linearly polarized in the direction of the polarization axis of the first polarizing plate 595 while passing through the first polarizing plate 595, and light that is not linearly polarized is absorbed. That is, only a portion of the circularly polarized light having a component coinciding with the polarization axis of the first polarizer 595 passes through the first polarizer 595, and since most of the remaining light does not coincide with the polarization axis, the first polarizer 595. Absorbed and extinguished. At this time, since the first polarizing plate 595 has a higher transmittance and a lower polarization degree than the second polarizing plate 591, the amount of light that is external light is smaller than that of the first polarizing plate 595 when it passes through the second polarizing plate 591. Absorbed and extinguished. That is, when light passes through the first polarizing plate 595, the degree of loss of light becomes small.

As described above, since most of the circularly polarized light disappears while passing through the first polarizer 595, the organic light emitting diode display 200 may have an effect of suppressing reflection of external light.

Next, the linearly polarized light passing through the first polarizing plate 595 is circularly polarized again while passing through the sixth phase retardation plate 596, and is then reflected by the electrodes 544 and 546 of the organic light emitting element L1 to form an axis. The direction changes by 180 degrees. In addition, the light may be reflected not only on the electrodes 544 and 546 of the organic light emitting element L1 but also on various metal wires.

Next, the circularly polarized light whose axial direction is changed by 180 degrees is linearly polarized again while passing through the sixth phase retardation plate 596, and then absorbed and disappeared by the first polarizing plate 595.

As described above, the remaining light passing through the first polarizing plate 595 passes through the sixth phase retardation plate 596, is reflected by the organic light emitting element L1, and then passes through the sixth phase retardation plate 596. Since the organic light emitting diode display 200 is extinguished by the first polarizer 595, the organic light emitting diode display 200 may have an effect of suppressing reflection of external light, thereby providing an organic light emitting diode display 200 having improved visibility.

Next, referring to FIGS. 12 and 13, the path of light emitted from the organic light emitting layer 545 (shown in FIG. 9) to the outside will be described.

12 and 13 are cross-sectional views and configuration diagrams showing a path through which light generated from an organic light emitting diode of the organic light emitting diode display according to the second exemplary embodiment of the present invention is emitted to the outside.

12 and 13, the light emitted from the organic emission layer 545 passes through the second electrode 546 and the sixth phase retardation plate 596. At this time, the light is a state in which various phases are mixed.

Next, the light passing through the sixth phase retardation plate 596 is directed to the first polarizer 595. At this time, the light coinciding with the polarization axis of the first polarizing plate 595 among the light passing through the sixth phase retardation plate 596 is linearly flattened while passing through the reflective first polarizing plate 595. At this time, since the first polarizing plate 595 has a higher transmittance and a lower polarization degree than the second polarizing plate 591, the amount of light that is internal light is smaller than that of the first polarizing plate 595 when passing through the second polarizing plate 591. Absorbed and extinguished. That is, when light passes through the first polarizing plate 595, the degree of loss of light becomes small.

The linearly polarized light passing through the first polarizer 595 becomes elliptical polarization while passing through the fifth phase retardation plate 593, which is a quarter wave plate. At this time, the optical axis of the fifth phase retardation plate 593 is distorted by 30 degrees from the polarization axis of the first polarizing plate 595. That is, the angle of intersection between the optical axis of the fifth phase retardation plate 593 and the polarization axis of the first polarizing plate 595 is 30 degrees.

As such, the pier between the axial direction of the linearly-lighted light passing through the first polarizing plate 595 and the optical axis direction of the fifth phase retardation plate 593 forms 30 degrees, so that the light is in the fifth phase retardation plate 593. ), It becomes an elliptical polarization. Although the pier between the axial direction of the linearly polarized light and the optical axis of the fifth phase retardation plate 593 becomes 45 degrees, the circularly polarized light becomes circular polarized light, but since the pier forms 30 degrees, the circularly polarized light does not become complete circularly polarized light and becomes elliptical polarized light.

Next, the elliptically polarized light passing through the fifth phase retardation plate 593 rotates by 15 degrees while maintaining the elliptical polarization while passing through the fourth phase retardation plate 592 which is a half wave plate. At this time, the optical axis of the fourth phase retardation plate 592 is distorted by 30 degrees from the polarization axis of the first polarizing plate 595. That is, the angle of intersection between the optical axis of the fourth phase retardation plate 592 and the polarization axis of the first polarizing plate 595 is 30 degrees.

In addition, the major axis direction of the elliptical polarized light rotated 15 degrees through the fourth phase retardation plate 592 is substantially the same as the polarization axis direction of the second polarizing plate 591. Therefore, the elliptically polarized light rotated by 15 degrees passes through the second polarizing plate 591 to be emitted to the outside even though the elliptically polarized state is not the linearly polarized state.

By such a configuration, light generated in the organic light emitting element L1 may be effectively emitted to the outside through the optical unit 59. Therefore, the loss of light emitted to the outside from the organic light emitting layer 545 can be minimized.

In addition, since the organic light emitting diode display 200 may efficiently emit light generated by the organic light emitting layer 545 to the outside, power for driving the organic light emitting layer 545 is reduced, and thus the organic light emitting diode display ( 200) the service life is improved.

Meanwhile, the optical unit 59 of the organic light emitting diode display 200 according to the second exemplary embodiment of the present invention is compared with the optical unit 58 of the organic light emitting diode display 100 according to the first exemplary embodiment. Since the number of phase retardation plates 592 and 593 used in FIG. 59 is reduced, an organic light emitting display device 200 having reduced manufacturing cost and manufacturing time is provided.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the following claims. Those who are engaged in the technology field will understand easily.

First polarizer 585, second polarizer 581, first phase delay plate 582, second phase delay plate 583, third phase delay plate 584

Claims (16)

An optical unit disposed on a light emitting unit from which light is emitted,
A first polarizing plate positioned on the light emitting unit;
A second polarizer disposed on the first polarizer and having a higher degree of polarization than the first polarizer; And
A plurality of phase delay plates positioned between the first polarizer and the second polarizer
Optical unit comprising a. In claim 1,
The first polarizing plate has a higher transmittance than the second polarizing plate. In claim 2,
The first polarizing plate comprises a matrix, iodine and a dye. 4. The method of claim 3,
The weight ratio of the iodine and the dye is 1: 1 to 1: 2 optical unit. In claim 1,
And an pier between the polarization axis of the first polarizing plate and the polarization axis of the second polarizing plate is 45 degrees. The method of claim 5,
The plurality of phase delay plates,
A first phase retardation plate being a half wave plate positioned between the first polarizing plate and the second polarizing plate;
A second phase delay plate which is a quarter wave plate positioned between the first polarizing plate and the first phase delay plate; And
A third phase retardation plate which is a quarter wave plate positioned between the first polarizing plate and the second phase retardation plate
Optical unit comprising a. In claim 6,
The pier between the polarization axis of the second polarizing plate and the optical axis of the first phase retardation plate is 17.5 degrees to 27.5 degrees,
And an angle of intersection between the polarization axis of the first polarizing plate and the optical axis of the first phase retardation plate is 17.5 degrees to 27.5 degrees. In claim 7,
The pier between the polarization axis of the second polarizing plate and the optical axis of the second phase retardation plate is 40 degrees to 50 degrees,
And an angle of intersection between the polarization axis of the first polarizing plate and the optical axis of the second phase retardation plate is 0 degrees to 5 degrees. 9. The method of claim 8,
The pier between the polarization axis of the second polarizing plate and the optical axis of the third phase retardation plate is 85 degrees to 90 degrees,
And an angle of intersection between the polarization axis of the first polarizing plate and the optical axis of the third phase retardation plate is 40 degrees to 50 degrees. In claim 9,
And the pier between the optical axis of the second phase retardation plate and the optical axis of the third phase retardation plate is 45 degrees. The method of claim 5,
The plurality of phase delay plates,
An additional phase retardation plate being a half wave plate disposed between the first polarizing plate and the second polarizing plate; And
A fifth phase retardation plate which is a quarter wave plate disposed between the first polarizing plate and the first phase retardation plate
Optical unit comprising a. In claim 11,
The pier between the polarization axis of the second polarizing plate and the optical axis of the fourth phase retardation plate is 10 degrees to 20 degrees,
And an angle of intersection between the polarization axis of the first polarizing plate and the optical axis of the fourth phase retardation plate is 25 degrees to 35 degrees. In claim 12,
The pier between the polarization axis of the second polarizing plate and the optical axis of the fifth phase retardation plate is 70 degrees to 80 degrees,
And an angle of intersection between the polarization axis of the first polarizing plate and the optical axis of the fifth phase retardation plate is 25 degrees to 35 degrees. In claim 1,
And an additional phase retardation plate disposed between said light emitting unit and said first polarizing plate. The method of claim 14,
And the pier between the optical axis of the additional phase retardation plate and the polarization axis of the first polarizer is between 40 degrees and 50 degrees. An organic light emitting device including a first electrode, a second electrode positioned on the first electrode, and an organic light emitting layer positioned between the first electrode and the second electrode and emitting light; And
An optical unit according to any one of claims 1 to 15, which is located on the organic light emitting element.
An organic light emitting display device comprising a.

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